Embodied energy
The embodied energy (carbon) of a building material can be taken as the total primary energy consumed (carbon released over its life cycle). This would normally include (at least) extraction, manufacturing and transportation. Ideally the boundaries would be set from the extraction of raw materials (including fuels) until the end of the products lifetime (including energy from manufacturing, transport, energy to manufacture capital equipment, heating and lighting of factory, maintenance, disposal etc.), known as ‘Cradle-to-Grave’. It has become common practice to specify the embodied energy as ‘Cradle-to-Gate’, which includes all energy (in primary form) until the product leaves the factory gate. The final boundary condition is ‘Cradle –to-Site’, which includes all of the energy consumed until the product has reached the point of use (ie the building site).
The figures included in the following table are a much-shortened and abbreviated adaptation of a survey published by the Sustainable Energy Research Team (SERT) of the University of Bath. The survey, ‘Inventory of Carbon & Energy (ICE)’ V2.0, was compiled and written by Prof. Geoff Hammond & Craig Jones, 2011. The full detailed survey, complete with original data, methodology and notes, is available from www.bath.ac.uk/mech-eng/sert/embodied/
The figures are based on a ‘Cradle-to-Gate’ analysis of publicly available information.
| Material | Energy MJ/kg |
Carbon kg CO2/kg |
Density kg /m3 |
| Aggregate | 0.083 | 0.0048 | 2240 |
| Concrete (1:1.5:3 eg in-situ floor slabs, structure) | 1.11 | 0.159 | 2400 |
| Concrete (eg in-situ floor slabs) with 25% PFA RC40 | 0.97 | 0.132 | |
| Concrete (eg in-situ floor slabs) with 50% GGBS RC40 | 0.88 | 0.101 | |
| Bricks (common) | 3.0 | 0.24 | 1700 |
| Concrete block (Medium density 10 N/mm2)) | 0.67 | 0.073 | 1450 |
| Aerated block | 3.50 | 0.30 | 750 |
| Rammed earth (no cement content) | 0.45 | 0.023 | 1460 |
| Limestone block | 0.85 | 2180 | |
| Marble | 2.00 | 0.116 | 2500 |
| Cement mortar (1:3) | 1.33 | 0.208 | |
| Steel (general - average recycled content) | 20.10 | 1.37 | 7800 |
| Steel (section - average recycled content) | 21.50 | 1.42 | 7800 |
| Steel (pipe - average recycled content) | 19.80 | 1.37 | 7800 |
| Stainless steel | 56.70 | 6.15 | 7850 |
| Timber (general - excludes sequestration) | 10.00 | 0.72 | 480 - 720 |
| Glue laminated timber | 12.00 | 0.87 | |
| Sawn hardwood | 10.40 | 0.86 | 700 - 800 |
| Cellular glass insulation | 27.00 | ||
| Cellulose insulation (loose fill) | 0.94 – 3.3 | 43 | |
| Cork insulation | 26.00* | 160 | |
| Glass fibre insulation (glass wool) | 28.00 | 1.35 | 12 |
| Flax insulation | 39.50 | 1.70 | 30* |
| Rockwool (slab) | 16.80 | 1.05 | 24 |
| Expanded Polystyrene insulation | 88.60 | 2.55 | 15 – 30* |
| Polyurethane insulation (rigid foam) | 101.50 | 3.48 | 30 |
| Woodwool board insulation | 20.00 | 0.98 | |
| Wool (recycled) insulation | 20.90 | 25* | |
| Straw bale | 0.91 | 100 – 110* | |
| Mineral fibre roofing tile | 37 | 2.70 | 1850* |
| Slate (UK – imported) | 0.1 – 1.0 | 0.006 – 0.058 | 1600 |
| Clay tile | 6.50 | 0.45 | 1900 |
| Aluminium (general & incl 33% recycled) | 155 | 8.24 | 2700 |
| Bitumen (general) | 51 | 0.38 - 0.43 | |
| Hardboard | 16.00 | 1.05 | 600 - 1000 |
| MDF | 11.00 | 0.72 | 680 – 760* |
| OSB | 15.00 | 0.96 | 640* |
| Plywood | 15.00 | 1.07 | 540 - 700 |
| Plasterboard | 6.75 | 0.38 | 800 |
| Gypsum plaster | 1.80 | 0.12 | 1120 |
| Glass | 15.00 | 0.85 | 2500 |
| PVC (general) | 77.20 | 28.1 | 1380 |
| PVC pipe | 67.50 | 24.40 | 1400* |
| Linoleum | 25.00 | 1.21 | 1200 |
| Vinyl flooring | 65.64 | 2.92 | 1200 |
| Terrazzo tiles | 1.40 | 0.12 | 1750* |
| Ceramic tiles | 12.00 | 0.74 | 2000 |
| Carpet tiles, nylon (Polyamide), pile weight 770g/m2 | 279 MJ/m2 | 13.7 / m2 | 4.6 kg/m2 |
| Wool carpet | 106.00 | 5.53 | |
| Wallpaper | 36.40 | 1.93 | |
| Wood stain / varnish | 50.00 | 5.35 | |
| Vitrified clay pipe (DN 500) | 7.90 | 0.52 | |
| Iron (general ) | 25 | 1.91 | 7870 |
| Copper (average incl. 37% recycled) | 42 | 2.60 | 8600 |
| Lead (incl 61% recycled) | 25.21 | 1.57 | 11340 |
| Ceramic sanitary ware | 29.00 | 1.51 |
Windows
| 1200 x 1200 2x glazed, air or argon filled | MJ per window | kg CO2 |
| Aluminium frame | 5470 | 279 |
| PVC frame | 2150 - 2470 | 110 - 126 |
| Aluminium clad timber frame | 950 - 1460 | 48 - 75 |
| Timber frame | 230 - 490 | 12 - 25 |
| 230 - 490 | 12 - 25 | |
| Krypton filled add: | 510 | 26 |
| Xeon filled add: | 4500 | 229 |
Paint
| Material | Energy MJ/m2 |
Carbon kg CO2/m2 |
| Water-borne paint | 59.0 | 2.12 |
| Solvent-borne paint | 97.0 | 3.13 |
Photovoltaic (PV) cells
| Material | Energy MJ/m2 |
Carbon kg CO2/m2 |
| Monocrystalline (average) | 4750 | 242 |
| Polycrystalline (average) | 4070 | 208 |
| Thin film (average) | 1305 | 67 |
Key: * - figures byGreenSpec obtained from publicly available information
Further information
• Sustainable Energy Research Team (SERT), - University of Bath - (bit.ly/biRxxM )
Disclaimer
GreenSpec accepts no responsibility or liability for any damages or costs of any type arising out of or in any way connected with your use of this web site. Data and information is provided for information purposes only, and is not intended for trading purposes. Neither GreenSpec nor any of its partners shall be liable for any errors in the content, or for any actions taken in reliance thereon.
